package ch01;

/**
 * Created by lenovo on 2017/10/29.
 */
public abstract class Duck {
    public  void quack(){
        System.out.println("鸭子呱呱叫......");
    }
    public  void swim(){
        System.out.println("鸭子会游泳......");

    }
    public void fly(){
        System.out.println("鸭子会飞起来......");

    }




    public abstract void display();



}
